Electron discharge device



June 5, 1934. w, HOLT ELECTRON DISCHARGE DEVICE Filed June 1928 Inventor Wm H023 Patented June 5, 1934 UNITED STATES PATENT CFFICE assignments, to Old Colony Trust Company, a corporation of Massachusetts Application June s, 1928, Serial No. 283,765

14 Claims.

This invention relates to electron discharge devices and is more particularly concerned with the supports for the contained elements, having for its object the improvement of both the mechanical and the electrical efficiency of such devices.

The invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawing:

Fig. 1 is a sectional elevation of a thermionic tube, looking toward the back of one of the plate 5 electrodes and embodying one form of the invention;

Fig. 2 is a similar View looking from the side of the tube between the edges of the two plate electrodes;

Fig. 3 is a detail showing the relation of the filament and the grid electrodes to the stem supports; and

Fig. 4 is a sectional plan of the stem press, on a somewhat enlarged scale, taken on a plane passing through the top edges of the wings of the press.

Referring to the drawing and to the exemplification of the invention therein shown, for illustrative purposes I have shown the same embodied in a thermionic tube of conventional type,

comprising the hermetically sealed and evacuated glass bulb 5, containing three elements, the latter comprising an anode composed of the two plate electrodes '7 and 9, herein of fine wire mesh,

the grid 11 of conventional type and the cathode or filament 13, the three elements being connected to and supported by the stem 15 at the bottom of the tube. The stem comprises a reentrant tubular member, united at its lower edges to the bulb, and formed into a stem press at its upper end to embed and hold the element supporting wires and hermetically seal the glass about the leading-in wires. The invention, however, has application to a wide variety of thermionic devices and to those employing any number of elements.

In order to provide a more efiicient distribution of the element supports, the stem press, or that portion of the stem in which the supports are embedded and which hermetically seals in the leading-in wires, is formed to provide a plurality of flattened extensions or branches arranged angularly with relation to each other. In the illustrated form of the invention, these extensions are arranged in two planes at right angles to each other, comprising (see Fig. 4) the opposite stem press branches 1'1 and 19 located in one plane, and the oppositely arranged stem press branches 21 and 23 located in a plane at right angles to that of the branches 1'? and 19, the four stein press branches radiating from the central portion of the stem, whereat is located the exhaust opening 25. The latter is employed for exhausting the tube and communicates with the tubulature 27, the lower end of which is sealed off and closed after exhaustion.

The supporting wires 29 and 31 for the filament, which are connected by leading-in wires to exterior terminals on the tube base, are embedded in the stem press branches 1'? and 19 re- 7 spectively, an anchor wire 33 for the mid portion of the filament being also embedded in the stem press in substantially the same plane with the wires 29 and 31. The grid supports 35 and 37, the first of which is also electrically connected to one of the base terminals, are also embedded respectively in the stem press branches 17 and 19, near the outer ends thereof and beyond the filament supports. The plate supports 39 and 41, on the other hand, are located in the stem press branches 21 and 23 respectively, occupying positions in a plane at right angles to the plane occupied by the filament and grid supports.

The glass walls of the stem press where each of the plate supporting wires 39 and 4:1 emerge therefrom are prolonged upwards for a substantial distance in the form of a sleeve-like jacket 42 of such internal diameter as to leave a substantial clearance about the wire. This may be conveniently'done by fusing to the stem at the time the press is formed a small length of glass tubing. This provides a much greater insulating separation measured over the superficial surface of the glass between the plate leads, on the one hand, and the filament and grid leads, on the other hand, since such separation is measured not only by the linear distance between the points of emergence of the leads from the stem press, but additionally by twice the height of the tubular sleeve, and the latter may be made greater or less as may be required for proper operating characteristics. This reduces the creepage across the stem surface, giving greatly increased efficiency and durability to the tube, particularly when high voltages are impressed on the plate, as in the case of power tubes.

The stem press branch 23 is prolonged to a greater extent than the branch 21 and also serves to carry near its outer end in the same plane with the plate support the anchor wire 43 supporting 110 at its upper end a body of insulating material, such as the glass anchor bead 45. In the anchor bead are embedded the plate anchor or supporting wires 4'7 bent toward and secured to the edges of the adjacent plate approximately intermediate its top and bottom, the two plate structures being further reinforced by cross connections 49 at their upper corners and similar connections 51 at their lower corners. To the anchor bead are also attached by embedment the anchor or supporting wires 53 secured to and designed to hold in fixed relationship the upper ends of the two grid supports and also two filament anchor or supporting wires 55, the bent ends of which are looped under the filament, the anchor wires for the several elements serving to maintain the various elements in their fixed, assigned relationship and stiffen and support the element assemblage at the end opposite the stem press.

In connection with the anchor bead an expedient is employed for increasing the surface separation of the supporting connections for the several elements similar to that employed in connection with a stem press. To this end, the anchor wires 47 for the plate are surrounded each by a spaced glass sleeve 57 integral with the glass bead 45 and extending up from the bead for a substantial distance, and the filament connections are surrounded by a similar but slightly longer sleeve 59.

This distribution of the element supports provides marked advantages both mechanically and electrically. It insures a rigidity of structure and a permanency in the initial assigned relationship of the elements, which is absent in the single plane type of stem press support where the assembly tends to throw out of aligned relationship when subjected to sudden jars. The multiplane disposition provides a certain mutual supporting relationship between the several sets of supporting wires, tending, under conditions of handling and shipping, to stifien the entire structure against displacement or misalignment of the elements, as, for example, the relative displacement of the plate and grid or the grid and filament. Thus it will be seen that the elements are connected to one set of five supporting wires arranged in one plane and another set of three supporting wires arranged in a plane at right angles thereto, the wires being substantially straight without substantial bends and the two sets together furnishing a stiffened truss-like support for the element structure. The rigidity of the element structure thus secured also tends to make the tube non-microphonic for air plane or other uses where it is subject to unusual vibration.

The step of assembling the parts is also greatly cheapened, simplified and rendered more accurate, inasmuch as the plural plane distribution of the supports precludes the necessity of bending or otherwises deforming the wires (with the exception of the filament anchor wire 33) so that, apart from the omission of the step of bending, less care, skill and time are required in the accurate installation of the elements.

The plural plane construction also renders possible a substantially greater spacing between the supporting terminals of the various elements than can be had by the single plane stem press, since additional space is available and a wider separation of the supports may be had through the location of the plate terminals and the grid and filament terminals in different branches of the stem press. This provides a much greater separation of plate terminals from both the terminals of the grid and. the terminals of the filament than may be had in the case of the ordinary stem press, and not only further increases the speed of assemblage but increases the insulation between the elements, reducing the creepage and leakage between the terminals of high and low voltage, and providing a lower internal capacity for the completed tube. This is of particular importance in the case of power tubes where high plate voltages are employed and where current leakage from the plate terminal tends rapidly to disintegrate the glass surrounding the sealed-in wires and to create air leakage through the stem press.

While I have herein shown for purposes of illustration a conventional type of tube having three elements and eight supporting connections, a lesser or greater number of supports may be employed and the branches of the stem press may be prolonged to provide the necessary space for additional supports as may be desired, or for supports for additional elements, or the stem press itself may be formed with additional angularly arranged branches or extensions so that the space available for properly separated supporting connections, which is materially restricted in the usual type of stem press, may be increased to any desired extent.

I claim:

1. In an electron discharge device, a press having a plurality of wings extending in more than one plane, a plurality of electrodes supported by said press, a plurality of upstanding supporting wires sealed in said wings, the wings in one plane carrying a number of said wires supporting the lower end of at least one of said electrodes, the wings in another plane carrying a number or" said wires supporting the lower end of at least another of said electrodes, the upper ends of said electrodes being mechanically connected together to support a number of said electrodes by wires lying in more than one plane.

2. In an electron discharge device, a press having a plurality of wings extending in more than one plane, a plurality of upstanding supporting wires sealed in said wings, the Wings in one plane carrying a number or" said wires supporting a plurality of electrodes, the wings lying in another plane carrying at least one of said wires connected to a supporting structure for the tops of said electrodes.

3. In an electron discharge device, a press hav ing a plurality of wings extending in more than one plane, a plurality of upstanding supporting wires sealed in said wings in a plurality of planes, a plurality of electrodes supported at their lower ends by said wires, and means for mechanically connecting the upper ends of said electrodes together, to support a number of said electrodes by wires lying in more than one plane.

4. In an electron discharge device, a press having a plurality of wings extending in more than one plane, a plurality of upstanding supporting wires sealed in said wings, and a plurality of electrodes supported by said press, said wires supporting the lower ends of said electrodes, and insulating means for mechanically connecting together the upper ends of all of said electrodes, whereby a number of said electrodes are supported by wires lying in more than one plane.

5. In a space discharge device, a press having a plurality of wings extending in more than one plane, a plurality of upstanding wire standards lying in more than one plane sealed in said wings, and a plurality of electrodes, said electrodes and said standards being mechanically connected together above said stem to form a rigid assembly in which said electrodes each are supported at one end by a number of said standards lying in one plane and also are rigidly connected to at least one of said standards lying in another plane.

6. A space discharge device comprising a discharge vessel, an electrode supporting winged stem in said vessel, three or more upstanding wire standards sealed into said stem at points, the outer ones of which form corners of a polygon transverse to the direction of the standards, and a plurality of electrodes, each having rigid connections from two or more spaced points to at least three of said standards lying in more than one plane to rigidly hold said electrodes.

'7. A space discharge device comprising a discharge vessel, an electrode supporting press having a plurality of wings lying in more than one plane in said vessel, three or more upstanding wire standards sealed into said wings at points, the outer ones of which form corners of a polygon transverse to the direction of the standards, and a plurality of electrodes, each having rigid connections from two or more spaced points to at least three of said standards lying in more than one plane to rigidly hold said electrodes, each electrode being insulated from one of its supporting standards and conductively connected to another of its conducting standards.

8. A space discharge device comprising a discharge vessel, an electrode supporting winged stem in said vessel, three or more upstandingwire standards sealed into said stem at points, the outer ones of which form corners of a polygon transverse to the direction of the standards, several electrodes supported on said standards insulated from each other, each of said electrodes having rigid connections from two or more spaced points to at least three of said standards lying in more than one plane to rigidly hold said electrode.

9. A space discharge device comprising a discharge vessel, an electrode supporting press having a plurality of wings lying in more than one plane in said vessel, three or more upstanding wire standards sealed into said wings at points, the outer ones of which form corners of a polygon transverse to the direction of the standards, several electrodes supported on said standards insulated from each other, said electrodes being each supported at one end by two of said standards and being rigidly connected at another end to another of said standards lying in a different plane than said first two standards to rigidly support said electrodes.

10. A space discharge device comprising a discharge vessel, an electrode supporting press having a plurality of wings lying in more than one plane in said vessel, three or more upstanding wire standards sealed into said wings at points,

the outer ones of which form corners of a polygon transverse to the direction of the standards, several electrodes supported on said standards insulated from each other, said electrodes each being supported at the bottom end by two of said standards being rigidly connected and at the top end to another of said standards lying in a different plane than said first two standards to rigidly support said electrodes, the sealing points of said three standards supporting an electrode forming corners of a triangle.

11. A space discharge device comprising a discharge vessel, an electrode supporting press having a plurality of wings extending in more than one plane in said vessel, a plurality of upstanding wire standards sealed in wings of more than one plane, a plurality of electrodes, said electrodes each being supported at one end by two of said standards and being rigidly connected at the other end to a third of said standards, the three standards so supporting an electrode being sealed in wings lying in more than one plane.

12. In a space discharge device, a winged stem, a plurality of electrodes supported by said stem, a plurality of upstanding wire standards anchored to said stem, said electrodes and said standards being rigidly mechanically connected together above said stem to form a rigid assembly, said standards, at the point at which they are anchored to said stem, lying in a plurality of non-parallel planes to provide a support for said rigid assembly resisting motion in a plurality of non-parallel planes.

13. In a space discharge device, a press having a plurality of wings extending in more than one plane, a plurality of electrodes supported by said press, and a plurality of upstanding wire standards sealed in said wings, said electrodes and said standards being rigidly mechanically connected together above'said stem to form a rigid assembly, said standards, at the points at which they are sealed in said wings, lying in a plurality of non-parallel planes to provide a support for said rigid assembly resisting motion in a plurality of non-parallel planes.

14. In a space discharge device, a press having a plurality of wings extending in more than one plane, a plurality of electrodes supported by said press, and a plurality of upstanding straight wire standards sealed in said wings, said electrodes and said standards being rigidly mechanically connected together above said stem to form a rigid assembly, said standards, at the points at which they are sealed in said wings, lying in a plurality of non-parallel planes to provide a support for said rigid assembly resisting motion in a plurality of non-parallel planes;

WILLIAM HOLT.

CERTIFIGATE OF CORREGTEON.

Patent No. i,%l,2i8. June 5, 1934.

WILLIAM HOLT.

It is hereby certified that errer appears in the printed specification of the above numbered patent requiring cerreetieii as feiiews: Page 2, lines 104, 117, 126, and 13S eiaims i, 2, 3, and 4, respectively, fer "an electron" read a space; page 3, line 81, claim 10, strike out the word "and" and insert the same before "being" in same iine; and that the said Letters Patent should be read with these eerreetiens therein that the same may conform to the record of the ease in the Patent Office.

Signed and sealed this 24th day of Judy, A. i), 1.934,

Bryan Bettey (Seal) Acting Commissioner of letentst 

